txt file that I download is empty - php

Question

The code below is for two purposes
1) I save a text file on my server in a folder named "backup_db" its working fine mean when I open that text file it contain all the data
2) At the same time i also make this file downloadable for a user so that he could download it for himself and could save it on his hard disk and according to my wish its downloading but unfortunately the .txt file saved on my hard disk is, when open its empty and i don't know why please help me out
//save file
$handle = fopen('backup_db/db-backup-'.date('d-m-Y_H-i-s').'-'.(md5(implode(',',$tables))).'.txt','w+');
$rr = fwrite($handle,$re);
//fclose($handle);
$ww = "db_backup".$rr.".txt";
//$handle = "";
header('Content-Disposition: attachment; filename=' . urlencode($ww));
header('Content-Type: application/force-download');
header('Content-Type: application/octet-stream');
header('Content-Type: application/download');
header('Content-Description: File Transfer');}}

Answer 1

You only set the HTTP header but did not write the file into the response body. Use either fpassthru() or readfile() to write the content of the file directly to the response.
Sample (taken from php.net)
<?php
$file = 'monkey.gif';
if (file_exists($file)) {
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
flush();
readfile($file);
exit;
}
?>
BTW:
Settings the same header multiple times simply overwrites the value set before unless you set the second parameter of header() to false.
Your code
header('Content-Type: application/force-download');
header('Content-Type: application/octet-stream');
header('Content-Type: application/download');
results in the following header:
Content-Type: application/download

Answer 2

Sending a file namein the header just gives the user a suggested filename. Try echoing out the contents of the file.

Answer 3

You should add
header("Content-Length: $size")
where $size is size of yout file in bytes.

Answer 4

Check this
ex :
$filename = urlencode($fileName); //download.txt
header("Content-Disposition: attachment; filename=\"" . $filename. "\";" );